Authors:

The ultrashort laser-matter interaction with femtosecond laser
pulse (fsLP) and moderate incident fluence is important for
fundamental physics of fast processes, warm dense matter physics
as well as for a wide range of industrial applications. Fast
heating of target material by fsLP results in formation of
thermo-mechanically stressed zone of 10-100 nm thick with
pressure 10-50 GPa. Its unloading may cause frontal cavitation
and ablation of subsurface layer at a crater depth of 50 nm for
aluminum and 100 nm for gold as our MD simulations and
experiments indicate. The ablation thresholds of Al and Au
obtained in simulations with the use of our new EAM potentials
agree with experimental data as well.
The compression wave propagating deep into material hits the rear
side of a target with formation of a rarefaction wave. The
last may produce cracks and spallation on rear side. MD
simulations of spallation of Al and Au films induced by fsLP show
that the used EAM potentials (Mishin et. al. and our new ones)
predict the different spallation thresholds while the shock wave
profiles are similar. Simulated spall strength of Al is 7.4 GPa,
that is noticeably less than 10 GPa obtained from acoustic
approximation with the use of velocity pullback on velocity
profile of free rear surface.

To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2009.SHOCK.T2.2